Not necessarily sedentary, it’s actually a process that has both properties of isolation and “mixture” in different quantities and over geography and time. People moved, then some stayed in places, then some moved again. Splitting and joining while moving and staying. But the Americas were pretty isolated once the land bridge went away. A flow path for makin’ babies was effectively cut off. Similar thing with what is now Australia and the surrounding islands, they used to be connected to Asia by a land bridge but were then fairly separated for probably 10k years or so, maybe more given that some groups were even more isolated within that subset.
Inbreeding is a guaranteed phenomenon, it is just a matter of degree. No matter how you want to make humans make babies with other humans, they share ancestry just like all of us do. We are all related, we all share common ancestry. But the question raised re: more recent shared parentage can change the result of this question. If you make the cutoff 10k years ago, then no we don’t all share parentage. Some people have a parental lineage that is distinct from another group of people, for that specific period. If you relaxed it to 50k it might vanish. If you relax it entirely you can ask what the mrca is, the most recent common ancestor, though that is a statistical estimate.
Basically I just want to point out that humans have dual character when it comes to us being related to one another. It’s similar to how different ethnic backgrounds often means people looking similar within the ethnic background but a bit different across them. All completely modern humans that are the same in every way that matters, but also with variation that is due to this spread-isolate-spread process.
This is also why medicine has problems with Eurocentricity. Many studies have focused solely on Euro patients and have not accounted for other genetic backgrounds or lifestyles. So they give wrong doses of drugs or misdiagnose, on top of all the cultural biases that discriminate what carr a person receives. Sickle cell anemia is a common example where it’s much more common for some ethnic backgrounds than others, reflecting populations that were somewhat separated and therefore acquired variation that established itself in one vs another population. Or lactose tolerance, which is actually the “odd one out” genetically speaking, not lactose intolerance.
Not necessarily sedentary, it’s actually a process that has both properties of isolation and “mixture” in different quantities and over geography and time. People moved, then some stayed in places, then some moved again. Splitting and joining while moving and staying. But the Americas were pretty isolated once the land bridge went away. A flow path for makin’ babies was effectively cut off. Similar thing with what is now Australia and the surrounding islands, they used to be connected to Asia by a land bridge but were then fairly separated for probably 10k years or so, maybe more given that some groups were even more isolated within that subset.
Inbreeding is a guaranteed phenomenon, it is just a matter of degree. No matter how you want to make humans make babies with other humans, they share ancestry just like all of us do. We are all related, we all share common ancestry. But the question raised re: more recent shared parentage can change the result of this question. If you make the cutoff 10k years ago, then no we don’t all share parentage. Some people have a parental lineage that is distinct from another group of people, for that specific period. If you relaxed it to 50k it might vanish. If you relax it entirely you can ask what the mrca is, the most recent common ancestor, though that is a statistical estimate.
Basically I just want to point out that humans have dual character when it comes to us being related to one another. It’s similar to how different ethnic backgrounds often means people looking similar within the ethnic background but a bit different across them. All completely modern humans that are the same in every way that matters, but also with variation that is due to this spread-isolate-spread process.
This is also why medicine has problems with Eurocentricity. Many studies have focused solely on Euro patients and have not accounted for other genetic backgrounds or lifestyles. So they give wrong doses of drugs or misdiagnose, on top of all the cultural biases that discriminate what carr a person receives. Sickle cell anemia is a common example where it’s much more common for some ethnic backgrounds than others, reflecting populations that were somewhat separated and therefore acquired variation that established itself in one vs another population. Or lactose tolerance, which is actually the “odd one out” genetically speaking, not lactose intolerance.